What's changing

Coming off a 12-4 campaign, the coaching staff remains intact. There's also reason to believe the NFL's eighth-ranked ground game can reach those heights again in 2013, but the Texans require new tools on offense. Playmakers in the passing game are a must to keep pace with the AFC's elite. With close to 20 unrestricted free agents on the roster -- most of them on defense -- the Texans must restock wisely or watch their Super Bowl window slam shut.

With the offseason officially under way, Around the League will examine what's next for all 32 teams.

Biggest free agents

» DE/OLB Connor Barwin: If Barwin isn't re-signed, Houston could be in trouble at both outside and inside linebacker. This position group was eaten alive last season after Brian Cushing went down. Barwin wasn't at his best in 2012, but the Texans can't afford to let him bolt.

» FS Glover Quin: Arguably the highest-priority signing for the Texans. Quin is an ideal fit for Wade Phillips' scheme and could be franchise tagged. Take a look at this year's Pro Bowl rosters -- top-tier safeties are rare. If he walks -- and we expect him to be retained -- opponents will thrive through the air.

» FB James Casey and RB Justin Forsett: Arian Foster and Ben Tate garner all the attention, but Casey was used in multiple ways as a lead blocker and pass-catcher out of the backfield last season. With Tate proving to be a brittle back, Forsett played a larger role than expected.

What they need

Right tackle is a concern, while a productive receiver across from Andre Johnson is a must. A field-stretching pass-catcher would provide Matt Schaub with positive matchups down field, helping the Texans move beyond their comfortable play-action package. Depth is a concern at every level on defense, depending on who leaves in free agency.

Offseason crystal ball

Before attacking the open market, the most important decisions begin at home. With 11 unrestricted free agents on defense (including three starters), the Texans must hold down the fort. Houston owns the No. 27 pick in the draft, and where they go in April might depend on who departs. Hard to call this a successful offseason unless the Texans upgrade at inside linebacker, right tackle and wide receiver.